Histamine H2 receptor antagonist (H2 blocker)Over the counter and by prescription

Pepcidfamotidine

Also sold as: Pepcid AC, Pepcid Complete, Ulcidine

An H2 blocker that reduces stomach acid within about an hour — useful for occasional or night-time heartburn where a PPI would be slower.

Quick answer

What it is: A histamine H2 receptor blocker. Histamine is one of the signals that tells stomach cells to make acid, and famotidine blocks that signal.
What it's used for: Heartburn and acid indigestion, reflux, and on prescription for ulcers and other acid-related conditions.
Worth knowing: It works within about an hour and lasts up to half a day, so it suits occasional symptoms and night-time reflux better than a PPI does.
Main safety point: It is cleared by the kidneys, so the dose is reduced in kidney impairment — important in older adults, where too high a dose can cause confusion.

Not sure which option is right for you? Pill4Me pharmacists in Chilliwack can help.

Call 604-705-3644 Book a doctor

Drug class

Histamine H2 receptor antagonist (H2 blocker)

Use in Canada

The most widely used H2 blocker in Canada since ranitidine was withdrawn from the market

What is Pepcid?

Famotidine reduces stomach acid production. Lower strengths are used without a prescription for heartburn and acid indigestion, including preventing symptoms before a meal known to trigger them. On prescription it is used for gastroesophageal reflux disease, stomach and duodenal ulcers, and other conditions involving excess stomach acid.

How Pepcid works

The cells that produce stomach acid respond to several signals, one of which is histamine acting on H2 receptors. Famotidine blocks those receptors, reducing acid production. Because it interrupts a signal rather than disabling the pump itself, it works faster than a proton pump inhibitor — within about an hour — but reduces acid less completely and for a shorter period.

Forms and strengths

Tablets, commonly 10 mg and 20 mg without a prescription, and 20 mg and 40 mg on prescription. Chewable tablets and combination products containing an antacid are also sold. Generic famotidine is inexpensive.

How Pepcid is taken

For occasional heartburn it can be taken when symptoms occur, or shortly before a meal expected to cause them. For night-time symptoms an evening dose is common. On prescription, dosing depends on what is being treated. Because famotidine is cleared by the kidneys, the dose is reduced when kidney function is impaired — this is one of the more commonly missed adjustments, particularly in older adults.

This is general information, not a dose for you. Dosing depends on the reason you are taking it, your kidney and liver function, your age, and everything else you take — follow the directions on your own label, and ask us if they differ from what you read here.

If you miss a dose

If you take famotidine as needed, there is no missed dose to make up. If it has been prescribed on a schedule, take it when you remember unless the next dose is nearly due, in which case skip it rather than doubling up.

Side effects

Common — usually manageable

Headache
Dizziness
Constipation or diarrhea
Nausea
Most people taking it short term have no side effects at all

Get medical help for these

Confusion, agitation or hallucinations — uncommon, and seen mainly in older adults and in people with reduced kidney function receiving too high a dose
Severe allergic reaction: swelling of the face or throat, difficulty breathing
A very slow or irregular heartbeat
Yellowing of the skin or eyes, which is rare but warrants assessment

Important warnings

Tell your pharmacist if you have reduced kidney function — famotidine is cleared by the kidneys and the dose usually needs to be lowered.

Heartburn needing treatment most days is a reason to be assessed rather than to keep buying an acid reducer.

Chest pain is not something to treat as heartburn. If it comes with sweating, breathlessness, or pain spreading to the arm or jaw, call 911.

Famotidine became the main H2 blocker after ranitidine was withdrawn from the Canadian market over an impurity concern. If you have old ranitidine at home, bring it to us for disposal rather than taking it.

Difficulty swallowing, vomiting blood, black stools or unintended weight loss need medical assessment.

Who should take extra care

Reduced kidney function: Famotidine is renally cleared and the dose is lowered when eGFR is reduced — worth confirming rather than assuming.
Older adults: The combination of age and reduced kidney function is where confusion and agitation are most often seen; a lower dose usually prevents it.
People with frequent symptoms: Needing it most days suggests a PPI or an assessment is more appropriate than ongoing H2 blocker use.
Pregnancy and breastfeeding: Reflux is common in pregnancy — ask which options are appropriate rather than self-treating long term.
People taking medications that need stomach acid: Reducing acid can lower absorption of some antifungals, HIV medications and iron salts.

Who should not take it

Known allergy to famotidine or other H2 blockers

Drug interactions

Famotidine has considerably fewer interactions than cimetidine, the older H2 blocker, because it does not inhibit the liver enzymes cimetidine affects. It can still reduce the absorption of medications that need stomach acid — atazanavir, ketoconazole, itraconazole and some iron salts — so spacing doses apart is sometimes advised. Antacids taken at the same time can reduce how much famotidine is absorbed. Because it is cleared by the kidneys, medications or conditions that reduce kidney function raise famotidine levels.

Commonly asked about alongside Pepcid: Pantoloc, Losec, Nexium.

This is not a complete list. If you take several medications, or buy anything over the counter, a pharmacist medication review is the reliable way to catch interactions that matter.

Coverage in British Columbia

Prescription famotidine is inexpensive and commonly covered, subject to your PharmaCare plan and indication. Lower-strength products bought over the counter are generally not a PharmaCare benefit. Coverage depends on the product and your plan — call 604-705-3644 and we will check yours.

Coverage may depend on indication, PharmaCare plan and Special Authority requirements. Ask Pill4Me Pharmacy to check your coverage, or see BC PharmaCare.

Frequently asked questions

Is famotidine better than omeprazole?

Neither is better in general — they suit different patterns. Famotidine works within about an hour and lasts up to half a day, which suits occasional heartburn, night-time symptoms, or taking before a meal you know will cause trouble. A PPI such as omeprazole reduces acid more completely but takes three to four days to reach full effect, which suits frequent symptoms or healing an inflamed esophagus. Some people use both at different times, which is worth planning with a pharmacist.

What happened to ranitidine (Zantac)?

Ranitidine was withdrawn from the Canadian market after testing found NDMA, a probable human carcinogen, in some products. Famotidine belongs to the same class but is a different molecule and was not affected. It is now the H2 blocker used in its place. If you still have ranitidine at home, do not take it — bring it to any pharmacy for safe disposal.

Can I take famotidine every day?

Short-term daily use is common and generally well tolerated. What is worth questioning is needing it most days on an ongoing basis, because that suggests the underlying reflux is not controlled and a different approach may work better. GERD and dyspepsia are both conditions a BC pharmacist can assess and prescribe for, so that conversation does not require a doctor's appointment.

Why does kidney function matter with famotidine?

Famotidine is cleared from the body by the kidneys. When kidney function is reduced, the drug accumulates, and at high enough levels it can cause confusion, agitation or hallucinations — most often in older adults. The fix is straightforward: a lower dose. It is one of the more commonly missed dose adjustments, so it is worth telling your pharmacist if your kidney function is reduced.

Can a pharmacist in BC prescribe something for my heartburn?

Yes. GERD and dyspepsia are both on the list of conditions BC pharmacists can assess and prescribe for under the Minor Ailments and Contraception Service, and PharmaCare covers the assessment fee for eligible BC residents whether or not a prescription is written. If your symptoms point to something needing investigation — swallowing difficulty, bleeding, weight loss — you will be referred to a physician instead.

Related medications

Pantoloc (pantoprazole sodium)Losec (omeprazole)Nexium (esomeprazole magnesium)

Conditions it’s used for

Acid Reflux & GERD

Not sure which option is right for you?

You don't need an appointment to ask. Our pharmacists can check this against your other medications and your health history, in the store or over the phone — there's no charge for the conversation.

Call 604-705-3644 Minor ailments service Transfer my prescription

Pill4Me Pharmacy is at 5625 Promontory Rd Unit 101, Chilliwack, BC. We deliver free to Chilliwack, Sardis, Promontory, Vedder and Yarrow, and you can reach a pharmacist directly at 604-705-3644.